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    <title>Document</title>
    <script>
        //更新变量
        var myname = '卧槽';
        console.log(myname);
        myname = '牛逼';
        console.log(myname);
        //声明多个变量
        var age = 18,
            address = '卧槽',
            gz = 20000;
        //声明不赋值 结果未定义

        //不声明直接赋值可行 但不提倡
    </script>
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<body>
    
</body>
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